This shining like silk and soft like velvet butterfly is Polyommatus icarus or Common blue. Only males usually have iridescent lilac blue with a thin black border uppersides. The female, pictured here, is brown above with a row of red spots along the edges and usually some blue at the base of the wings; the extent of blue and brown is extremely variable; Undersides have a greyish ground colour in the males and a more brownish in the females.
This species is widespread over much of the Palaearctic in temperate Asia and Europe.
These butterflies inhabit flowery or grassy places, warm and cool, open or wooded areas and at all altitudes up to high alpine meadows at an elevation of 0–2,700 metres above sea level.
The larva feeds on plants from the family Leguminosae (bean family).
The caterpillar is small, pale green with yellow stripes. They are attractive to ant, but not as much as some other species of blues. The chrysalis is olive green/brown and formed on the ground, where it is attended by some ants’ genera which will often take it into their nests. The larva creates a substance called honeydew, which the ants eat while the butterfly lives in the ant hill.